1. Field of the Invention
The present invention relates to wind turbines, and particularly to an adaptive pitch control system for wind generators.
2. Description of the Related Art
Because of diminishing oil reserves and environmental concerns, renewable energy research is getting momentum. Wind energy in itself encompasses various engineering fields and is rapidly developing into a multi-disciplinary area of research and experimentation. In wind generation systems, the variable speed doubly fed induction generator (DFIG) is preferred over the permanent magnet synchronous generator (PMSG) type for its versatility.
The control of blade pitch angle is a necessary part of variable speed wind turbines, since by controlling the pitch angle, the aerodynamic power that flows through to the generator can be adjusted. The system dynamics relied upon in some installations use a PI controller. Many installations use Fuzzy logic to find the pitch controller parameters. A self-tuning fuzzy-PID controller has been described in the related art. Robust controllers for output power leveling of variable speed variable pitch wind turbine generator systems are also available in the literature. The use of generalized predictive control has also been reported. Moreover, the literature reports a neural network capable of self-tuning for different operating conditions.
Thus, an adaptive pitch control system for wind generators solving the aforementioned problems is desired.